Random access tape machine

ABSTRACT

A digitally controlled magnetic tape system provides storage and retrieval of information in accordance with random accessing and affords branching within the program recorded on the tape. Both random accessing and branching operations are performed at high speed for either forward or reverse directions of tape drive to position the tape at a desired, specified address. The digital control also affords ancillary control functions for providing synchronized operation of external devices, such as visual aids, in replay of the tape. The system provides both for the preparation of a programmed tape and automatic playback of that tape in accordance with the recorded program and in response to various input controls coordinated with the program. The system has particular application as a teaching machine wherein an instructor may record a lecture, a question, and multiple choice answers. An evaluation of each proposed answer may then be recorded, with a corresponding control word. Selection of a given answer choice by a student in subsequent play operations automatically presents the instructor&#39;&#39;s comment to the student, and may provide a grading and scoring operation. Reading of the control word causes the system to automatically present the next instructional segment as defined by the program, and in accordance with the automatic branching and random accessing capabilities of the system. Manual control of the play operation is provided, such as random accessing, to select a tape position for initiation of the program and to permit repeat of questions, while assuring proper operation of the machine in accordance with the desired program.

United States Patent 1 Staas, Jr.

111 3,745,531 [451 July 10,1973

Inventor:

US. Cl. 340/1725, 340/174.1 Int. Cl. G111) 5/00 Field of Search 340/1725, 174.1,

[56] References Cited UNITED STATES PATENTS 12/1969 Cameron et a1. 340/1725 7/1964 Chapman et 35/9 A 12/1966 Fein 179/1001 11/1967 Talarczyk 340/1725 9/1966 Walker 35/9 A 7/1967 Roberts et a1. 179/1002 S 1/1968 Tillotson et a1 35/9 A Primary ExaminerPaul J. Henon Assistant Examiner-Mark Edward Nusbaum Attorney-Irons, Sears, Staas, Halsey and Santorelli 5 7 ABSTRACT A digitally controlled magnetic tape system provides storage and retrieval of information in accordance with random accessing and affords branching within the program recorded on the tape. Both random accessing and branching operations are performed at high speed for either forward or reverse directions of tape drive to position the tape at a desired, specified address. The digital control also affords ancillary control functions for providing synchronized operation of external de vices, such as visual aids, in replay of the tape. The system provides both for the preparation of a programmed tape and automatic playback of that tape in accordance with the recorded program and in response to various input controls coordinated with the program. The system has particular application as a teaching machine wherein an instructor may record a lecture, a question, and multiple choice answers. An evaluation of each proposed answer may then be recorded, with a corresponding control word. Selection of a given answer choice by a student in subsequent play operations automatically presents the instructor's comment to the student, and may provide a grading and scoring operation. Reading of the control word causes the system to automatically present the next instructional segment as defined by the program, and in accordance with the automatic branching and random accessing capabilities of the system. Manual control of the play operation is provided, such as random accessing, to select a tape position for initiation of the program and to permit repeat of questions, while assuring proper operation of the machine in accordance with the desired program.

54 Claims, 30 Drawing Figures LOGlC OUTPUTS CONTROL PROCESS INPUTS CONTROL 4 MODEM TAPE SEQUENTIAL CONTROL LOGIC PATENIEU 3. 745. 531

SHEU 010F213 INVENTOR PHILIP C STAAS, JR.

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42 46 48 44 F??? FR FF 5 52 T PRESS EDIT SP JL PLAY STTOP A B c D END RECORD g 33 BR F |G.|B

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sum 08% 23 E M I FIG. 60

DRIVE' DRWE S"EAKER SPEAKER i} FF E PAIENIEU 4m 1 01m W h 225 m E H M mm W W M aim ,zunmmom m S $25 05 ea; mo 02 6M. W25 02 has oz 22 2: mm; E mm m5 02 M 65% Q m 02 gr a m m; m h M 1 PAIENTED JUL 1 0191s sum as or 23 mEoE PAIENIEuJuL 1 0 ms SIEET 09 0f 23 M IIL PATENIEU 101975 3, 745,531

SEN 130F 23 ririrhl m? ullwllliilligbllj wz m PATENIEU 3. 745.531

SHE! 15M 23 FIGJIB FEXOR PAIENIEDJUL 1 0 ms sum 18 or 3 SERlN SERBL FIG. I2B 

1. A system for recording information to be reproduced in accordance with a desired program, said system utilizing a recording medium and being operable in a record mode to simultaneously record the information in an information track and digital words in a control track of the medium, the digital words including index words of an ordered sequence for defining positions in said medium and control words defining respectively corresponding operations to be performed for controlling reproduction of the information from the medium in accordance with the desired program, comprising: means for rendering said system opErable in a record mode, means for recording information in the information track of said medium, means operable in the record mode of said system during recording of information for generating an ordered sequence of digital index words for recording in the control track of the medium during corresponding, periodic recording intervals, means for producing control inputs to said system to effect recording of corresponding control words, means responsive to each such control input for generating a corresponding control word to be recorded, and means selectively controlling the recording of index and control words and operable in response to each such control input to effect recording of the corresponding control word in the control track of the medium in lieu of a next index word of the sequence and during the next successive recording interval.
 2. A system as recited in claim 1 wherein: said means responsive to a control input momentarily disables said index word generating means from operating a further index word of the sequence in response to receipt of a control input and said index word generating means again being enabled following recording of a control word corresponding to the control input to resume the generation of the said sequence of index words.
 3. A system as recited in claim 1 wherein the digital words have a fixed format of bit positions including control bit positions and wherein: said index word and said control word generating means include means normally operable to encode the control bit positions of each digital word in each periodic recording interval to define an index word, and selectively operable in response to said control inputs to automatically encode said control bit positions to define the respectively corresponding control words.
 4. A system as recited in claim 3 wherein the digital words are periodically made input to said recording means, and wherein: said digital words further include a plurality of additional bit positions associated with said control bit positions, and there is further provided: storage means having a number of bit storage positions corresponding to the control and associated additional bit positions of the digital words, first gating means for supplying the encoded bits of the associated bit positions identifying the index number, from said index number generating means to said respectively associated bit storage positions of said storage means, second gating means for supplying the encoded control bit positions from said control bit position encoding means to the corresponding bit storage positions of said storage means, and means for deriving from said storage means a serial bit train corresponding to the bits stored in the bit storage positions thereof for recording in said recording medium during each said periodic recording interval.
 5. A system as recited in claim 4 wherein said storage means comprises a shift register.
 6. A system as recited in claim 4 wherein there is further provided: further encoding means responsive to predetermined ones of said control inputs to automatically define encoded bits correspondings to at least selected ones of said additional associated bit positions, and third gating means associated with said further encoding means and responsive to receipt of said predetermined ones of said control inputs to supply the encoded bits produced by said further encoding means to the respectively corresponding bit storage positions of said storage means.
 7. A system as recited in claim 5 further providing for converting the digital bits of information of the serial bit train to analog form for recording in a magnetic recording medium, further comprising: means for generating a cyclic signal of predetermined frequency, and means selectively responsive to the logic 1 and logic 0 data bits of the digital serial bit train and to said generating means to produce corresponding first and second groUps of cycles of said cyclic signal, each said group comprising a predetermined and respectively associated number of cycles of said cyclic signal, thereby producing for the successive data bits of the digital information an analog signal of successive, respectively corresponding groups of cyclic signals of the predetermined cyclic frequency and of a number of cycles respectively corresponding to the logic 1 and logic 0 value of the said data bits for recording in the control track of the recording medium.
 8. A system as recited in claim 7 wherein there is further provided: a clock generator producing a clock pulse output of lower frequency than said cyclic signal, and said cyclic signal generating means is enabled for generating a cyclic signal output of the predetermined frequency in response to each such clock pulse and for the duration thereof.
 9. A system as recited in claim 8 wherein said means for producing said first and second groups of cycles of said cyclic signal comprises: counting means receiving the cyclic signal output of said cyclic signal generator for counting the cycles thereof and producing outputs corresponding to counting of the predetermined numbers of said cycles respectively associated with said first and second groups, and gating means receiving the cyclic signal output of said cyclic signal generator, the count indicating outputs of said counting means and the corresponding data bits of the digital information and selectively enabled thereby to effect gating through of the respectively corresponding predetermined numbers of cycles of the groups thereof in accordance with the logic 1 or logic 0 value of the data bits.
 10. A system as recited in claim 6 further including: a timing circuit initiated in operation in response to initiation of recording operations to define the periodic recording intervals and defining within each said periodic recording interval an initial blanking interval prior to recording and a second time portion defining the time operations of the recording functions, decision logic means responsive to said timing means and to recognition of a control input to effect a decision, at the initiation of the recording time portion of said periodic recording interval, to record an index word or to record a control word and to maintain that decision for the duration of the periodic recording interval, and said decision logic means further being responsive to said timing circuit to selectively enable said first and second gating means in accordance with the decision to record an index word or a control word and, in accordance with that decision, to interrupt the further sequential generation of index numbers by said index number generator for each recording interval in which the decision is to record a control word.
 11. A system as recited in claim 10 wherein said decision logic circuit further is responsive to said timing means to lock the encoded bits of said control bit positions and said associated bit positions of the digital word into the corresponding bit storage positions of said storage means and to prevent receipt by said storage means of any further bits for the duration of the recording interval.
 12. A system as recited in claim 10 wherein said decision logic circuit is further responsive to said timing means to initiate serial read-out of the stored bits from said storage means for recording in the control track of said medium, and to reset said storage means at the conclusion of said recording interval.
 13. A system as recited in claim 1 wherein there is further provided: means to establish an edit substate of said system to enable recording of a control word within a previously recorded portion of the medium and responsive to an edit control input to establish the edit substate, and means responsive to a control input to said machine during the edit substate thereof for effecting recording of a control word in the record track of said mEdium and upon completion of recording thereof to terminate the edit substate.
 14. A system as recited in claim 13 wherein there is further provided: means for establishing an index number corresponding to the beginning of the said previously recorded portion, means for supplying that index number as an input to said system, and means responsive to the index number thus supplied to preset the index number generating means to that count for initiating the generation of the sequence of index numbers from that count in subsequent recording.
 15. A system as recited in claim 1 further operable in a play mode to read digital words from the control track of the medium and further responsive to control inputs to the machine to control the reproduction of the audio information from the information track in accordance with a desired program, further comprising: means for rendering said system operable in a play mode, means for reading information from the information track of said medium in said play mode, means for reading the digital words from the associated control track of said medium in said play mode, means for enabling both said information track and said control track reading means to effect simultaneous reading of the corresponding tracks during system operation for reproduction of information, and means responsive to said digital word reading means and selectively operable in accordance with reading of index words to determine a unique location within said medium corresponding to an address as defined thereby, and operable in accordance with reading of control words to automatically establish the respectively corresponding system operations.
 16. A system as recited in claim 15 further including: shift register means for receiving as a serial input the bits of each encoded digital word read from the said medium by said reading means, storage means for receiving from said system a digital word corresponding to a particular control word recorded on said medium, comparator means for determining the sign and magnitude difference of a digital word from said storage means and a digital word from said shift register in said play mode to compare the data bits of each digital word read from said medium with the corresponding data bits of each digital word in said storage means, and gating means associated with said shift register to read out the data bits from said shift register, and enabled in said play mode in response to each digital word read from said medium to enter the digital word thus read into said comparator.
 17. A system as recited in claim 16 wherein the digital word supplied to said storage means comprises an index control word identifying an index number address of said medium and wherein there is further provided: means responsive to said comparator means for searching said medium to locate the desired address thereof, and said comparator means identifies the location of said desired address when the digital word read from said medium corresponds to the digital word of said storage means.
 18. A system as recited in claim 16 further including: means for inhibiting entry of data bits into said shift register during an initial interval of acceleration or deceleration relative to a transport speed of said recording medium for recording thereon in the record mode and for read out of digital words therefrom in the play mode of operation.
 19. A system for reproducing information from a recording medium in accordance with a desired program defined by controls recorded on said medium and wherein the information to be reproduced is recorded on said medium in an information track and the controls are recorded on said medium in an associated control track and comprise digital words recorded at periodic intervals therein, the digital words including index words defining addresses of said medium and control words defining operations of said system in accordance with the desired Program for controlling reproduction of information from said medium, comprising: means for reading information from the information track of said medium, means for reading the digital words from the associated control track of said medium, means for enabling both said information track and said control track reading means to effect simultaneous reading of the corresponding tracks during system operation for reproduction of information, and means responsive to said digital word reading means operable to determine the corresponding addresses of said medium in accordance with the reading of index words recorded in said medium, said means to determine including means to distinguish between index and control words in accordance with reading of control words to automatically establish the respectively corresponding system operations.
 20. A system as recited in claim 19 further including: means for establishing a desired address of the medium to be located in accordance with the number of the index word defining that address, means responsive to an index control input to effect an address search of said medium in accordance with reading of the digital words from the control track thereof, and means for comparing the index number of the desired address with the index number of each index word read from the medium to terminate the address search by said address search means when the desired address of the medium is located.
 21. A system as recited in claim 19 wherein said simultaneous reading means is enabled only for reading of digital words during said address search and is inoperable to read the information from the information track during the address search.
 22. A system as recited in claim 21 wherein said address search means is operable, upon said comparison means establishing that a desired address has been located, to enable said reading means to read information from the information track of the medium simultaneously with reading of a control track thereof.
 23. A system as recited in claim 20 wherein the index words are recorded in said control track in an ordered sequence, and wherein: said address search means is operable to effect relative movement of said medium and said reading means in opposite directions and initially to effect said movement in a first direction for reading of index words therefrom by said reading means and supply thereof to said comparison means for a first comparison to determine if the index numbers of the index words being read are greater than the index number of the desired address, said address search means being responsive to said comparison means if said first comparison is satisfied to effect said relative movement in a second direction until the opposite comparison is satisfied by said comparison means that the number of the index words read from the tape is less than the index number of the desired address, and said address search means is thereupon operable to effect said relative movement to locate the desired address in accordance with the comparison by said comparison means that the index number of the desired address and that of an index word read from the tape are equal, thereby to initiate reproduction of information from said medium beginning at the desired, located address.
 24. A system as recited in claim 19 wherein the information track contains at least one segment of information and plural portions within that segment to be selectively reproduced, each such portion of the segment having associated therewith a control word in said control track and corresponding to the beginning of said portion, and wherein said system further includes: means selectively operable by an operator of said system to establish a control input designating for reproduction a portion of information contained within a segment and identified by the corresponding control word in the associated control track, and means responsive to said control input means for effecting a search of said medium for identifying the location of the corresponding control word and to effect reproduction of information in that portion of the segment designated by the corresponding control word.
 25. A system as recited in claim 24 wherein said search means comprises: control means for selectively effecting relative movement of said medium and said reading means at a drive speed for reading of information and of digital words from said corresponding tracks, and at fast forward and fast reverse speeds for reading of only said digital words from the corresponding control track during searching, said search means defines, in accordance with the control inputs, the direction of relative movement required for locating the portion thereby identified for reproduction, and said control means is responsive to said search means to drive said medium selectively in the forward and reverse directions at the fast speed to locate the corresponding control word, and at drive upon location thereof for reproduction of the information of that portion.
 26. A system as recited in claim 19 wherein there is recorded in said medium a control word containing an index number defining an address of said medium for automatic branching to that defined address, comprising: means responsive to reading of a branching control word to effect an address search of said medium in accordance with reading of the digital word from the control track thereof, and means for comparing the index number of the desired address derived from said branching control word with the index number of each index word read from the medium to terminate the address search by said address search means when the desired address of the medium is located.
 27. A system as recited in claim 19 further including: means for generating control inputs to said system by an operator of said machine to control system operations, and sequential logic means defining permitted sequences of operation of said system in response to control words read from said medium and the control inputs generated by an operator and inhibiting any response to control inputs inconsistent with the established sequence.
 28. A system as recited in claim 19 wherein said recording medium comprises a magnetic tape.
 29. A system as recited in claim 28 wherein said magnetic tape is provided in a tape cassette.
 30. A system as recited in claim 19 wherein said recording medium comprises a magnetic tape and wherein there is further provided: means for transporting said tape at drive, fast forward, and fast reverse speeds, means for establishing an indexing operation of said system to drive said tape at a fast transport speed to position said tape at a desired address as defined by a designated index number and corresponding to an index word having that number and defining the desired address, and means for selectively enabling the reading of information from said information track only in the normal drive speed of said transport means.
 31. A system as recited in claim 19 wherein the digital words have a fixed format of bit positions including control bit positions distinguishing index and control words and defining each of a plurality of control words, further comprising: means for receiving digital words read from the control track of the tape to distinguish and identify each bit thereof in accordance with the format of the digital words, and means responsive to the control bit positions of the digital words read from the tape to automatically produce the system operation identified thereby.
 32. A system as recited in claim 31 further comprising: means for transporting said medium for reading in a forward drive speed and in fast forward and fast reverse speeds, and means responsive to the direction of transport of said medium including gating means associated with the outputs of said digital word bit position receiving means and enabled in accordance with the direction of transPort of the medium to select the correct bit positions as the control bits of the digital word read from the tape.
 33. A system as recited in claim 32 wherein the digital words further include in the format thereof a plurality of additional bit positions associated with said control bit positions, and wherein: said digital word receiving means includes bit storage positions corresponding to each bit position of the digital word format for storing in the respectively corresponding bit storage positions thereof the coded bits of each digital word read from the control track of the medium, and said gating means includes a plurality of bit gating means respectively associated with each bit storage position of said receiving means.
 34. A system as recited in claim 33 further comprising: means for generating a clock pulse in response to reading of each digital word from said medium, means responsive to each said clock pulse for enabling entry of the bits of each said digital word into said storage means, and means responsive to entry of a complete digital word for generating as outputs of said storage means, the data bits from the data bit storage positions of said storage means.
 35. A system as recited in claim 34 further comprising: means for storing a digital word defining a position of the medium to be addressed, and comparator means responsive to said address storage means and to said storage means for the digital words read from said medium to determine when the medium is positioned at the desired address.
 36. A system as recited in claim 35 wherein: the digital word defining a desired address is derived from a control word read from the medium, thereby to effect an automatic branching operation of said system.
 37. A system as recited in claim 35 wherein the digital word defining a desired address is derived from a control input supplied to the system.
 38. A system as recited in claim 37 wherein the control input comprises an indexing control to effect a random access search of the medium for a desired address.
 39. A system as recited in claim 24 wherein the recorded information comprises a teaching program and each segment comprises a lesson and the portions thereof comprise at least a first portion including a question and associated multiple choice answers and a further portion corresponding to the selection of each such multiple choice answer and wherein a stop control word is recorded at the completion of the multiple choice answers and prior to the answer selection response portions and each such answer selection portion is preceded by a respectively corresponding answer control word, and wherein the system further comprises: means responsive to the reading of a stop word by said reading means for stopping further reading of said medium, means responsive to an answer selection control input by an operator of the system to initiate search of that segment by said search means to locate a control word corresponding to the answer selection control input and designating the answer selection response portion of that segment, and said system thereupon reproducing that portion of the segment designated by and associated with the corresponding answer control word.
 40. A system as recited in claim 22 wherein: said search means is responsive to reading of answer control words not conforming to the answer selection control input to effect continued search of said medium.
 41. A system as recited in claim 24 wherein a question start word is recorded in the control track simultaneously with the initiation of said first portion comprising the question and wherein there is further provided: means responsive to a question repeat control input by an operator of the system to initiate search of that segment by said search means to locate the question start control word, and said system thereupon reproduces that question portion of the segment as designated by and associated with the corresponding question start word.
 42. A system as recited in claim 19 wherein the signals read from the recording medium comprise groups of cyclic signals and wherein the system further includes means operable for converting the cyclic signals thus read to a digital format of logic 1 and logic 0 data bits and comprises: means responsive to each group of cycles read from the medium to identify the receipt thereof, second counting means for counting the number of cycles in each said group to define the data bit value thereof as logic 1 or logic 0, accordingly, said counter being responsive to said group receiving means to be reset upon the completion of receipt of said group, and means responsive to the output of said second counting means and to said cycle group identifying means to be enabled by the latter upon completion of receipt of a group of cycles to produce an output of logic 1 or logic 0 data bits in accordance with the count accumulated by said counter.
 43. A system as recited in claim 42 wherein there is further provided: output gating means for producing a clock pulse in response to said cycle group identifying means identifying completion of receipt of a cycle group in reading of said medium.
 44. A system for reproducing information from a recording medium in accordance with a desired program defined by digital control words recorded on said medium and wherein the information to be reproduced is recorded on said medium in an information track and the control words are recorded on said medium in an associated control track and define corresponding operations of said system in accordance with the desired program for controlling reproduction of information from said medium, and wherein the information track contains at least one segment of information and plural portions within that segment to be selectively reproduced, each such portion of the segment having associated therewith a control word in said control track and corresponding to the beginning of said portion, comprising: means for reading information from the information track of said medium, means for reading the control words from the associated control track of said medium, means for enabling both said information track and said control track reading means to effect simultaneous reading of the corresponding tracks during machine operation for reproduction of information, means selectively operable by an operator of said system to establish a control input designating for reproduction a portion of information contained within a segment and identified by the corresponding control word in the associated control track, means responsive to said control input means for effecting a search of said medium for identifying the location of the corresponding control word and to effect reproduction of information in that portion of the segment designated by the corresponding control word, and wherein said search means includes control means for selectively effecting relative movement of said medium and said reading means at a drive speed for reading of information and of control words from said corresponding tracks, and at fast forward and fast reverse speed for reading of only said control words from the corresponding control tracks during searching, said search means defines, in accordance with the control inputs, the direction of relative movement required for locating the portion thereby identified for reproduction, said control means is responsive to said search means to drive said medium selectively in the forward and reverse direction at the fast speed to locate the corresponding control word, and at drive upon location thereof for reproduction of the information of that portion, and means responsive to said digital control word reading means and operable in response to reading of each such control word to automatically establish the respectively corresponding system operation.
 45. A system for recordIng information to be reproduced in accordance with a desired teaching program and operable in a record mode to simultaneously record audio information, comprising a sequence of instructional segments, each segment including at least a question and associated multiple choice answers and comments on each answer selection, in sequence, in an information track of a recording medium and digital words for controlling reproduction of the instructional sequence, in an associated control track of the recording medium, comprising: means for rendering said system operable in a record mode, audio response means for generating a signal for recording of the audio instructions in the information track of said medium in the record mode, means for generating index words of an ordered sequence for recording in said control track of said medium in periodic recording intervals in the record mode of said system to define addressable positions of said medium for selective reproduction in the play mode of said system, and means for selectively recording control words in response to control inputs to said system during the record mode in lieu of index words within said periodic intervals, means operable in the record mode of said system for receiving control inputs and producing in response thereto digital control words for recording in the control track for controlling reproduction of the instructional sequence in accordance with a desired program.
 46. A system as recited in claim 45 further comprising encoding means responsive to a plurality of control inputs for producing respectively corresponding digital control words and including a stop control word to be recorded upon completion of recording of a question and an answer control word recorded at the initiation of recording of each answer selection comment.
 47. A system as recited in claim 46 operable in a play mode to reproduce the instructional sequence in accordance with the desired program established by the recorded control words and comprising: means responsive to a stop control word for interrupting further reproduction of information from said medium, means for receiving control inputs identifying answer choice selections in the play mode, and means operable to effect a search of said medium to locate the corresponding recorded answer control word within a given instructional segment for reproduction of the associated audio information.
 48. A system as recited in claim 47 wherein said search means is responsive to reading of answer control words in conforming to the answer selection control input to effect continued search of said medium.
 49. A system as recited in claim 46 wherein there is further provided: means for producing a question start control input, said encoding means responding thereto to generate a question start control word to be recorded on said medium at the initiation of recording of a question, and there is further provided means for receiving a question repeat control input in the play mode, and said search means is operable to search said medium within the corresponding segment to locate the question start control word in response to the question repeat control input and to automatically repeat the reproduction of that question.
 50. A system as recited in claim 45 wherein there is further provided: means for producing a branching control input and including an index number identifying an address in said medium to which branching is to be effected in accordance with the program upon reading of the branch control word in the play mode.
 51. A system as recited in claim 45 further comprising: means for producing an edit control input to establish an edit substate of the system, and means responsive to the edit substate and to a further control input to effect recording of a corresponding control word and simultaneous erasing of a previously recorded control word in the control track of the medium and thereupon to terminate further Recording in the edit substate upon completion of recording of the control word.
 52. A system as recited in claim 51 wherein said means responsive to the edit substate includes means for effecting a delay in recording of the control word subsequent to receipt of the control input to effect the recording thereof, thereby to permit proper relative movement of the recording medium and the recording means to assure proper recording of the control word.
 53. A system as recited in claim 52 wherein there is further provided: means for establishing a predetermined index number, and means for initializing said index number generator at the established index number, thereby to effect generation of the ordered sequence of digital words from the established index number.
 54. A system as recited in claim 46 wherein there is further provided: means for automatically encoding an answer control word to identify correct multiple choice answer selections. 